公开(公告)号：US20150301092A1

公开(公告)日：2015-10-22

申请号：US14438735

申请日：2013-11-26

Applicant: ST-Ericsson SA

Inventor： Vratislav Michal

IPC: G01R19/25

CPC classification number: G01R19/25 ,  H02M3/158 ,  H02M3/1588 ,  Y02B70/1466

Abstract: There is described a circuit and a method of detecting a voltage polarity for the detection of a Continuous Conduction Mode to Discontinuous Conduction Mode boundary of a switched DC-DC converter. There is provided use of a dynamic current mirror to store in a first capacitor (C) a voltage representative of the conduction voltage (VDS(Φ1)) of the power switch, at the end of a conduction cycle of said power switch. Also, an auto-zero comparator is used to charge the output voltage of the dynamic current mirror into a second capacitor (C2), during the first phase of operation corresponding to a conduction cycle of the power switch, and to detect the polarity of the conduction voltage (VDS(t=TCLK)) of the power switch at the end of the first phase of operation of the DC-DC converter, by comparing the voltage stored in the second capacitor during the first phase of operation with the output voltage of the dynamic current mirror in a second phase of operation (Φ2) corresponding to a non-conduction cycle of the power switch.

Abstract translation: 描述了用于检测开关DC-DC转换器的连续导通模式到不连续导通模式边界的电压极性的电路和方法。 在所述电源开关的导通周期结束时，提供使用动态电流镜以在第一电容器（C）中存储表示电源开关的导电电压（VDS（Φ1））的电压。 此外，在对应于电源开关的导通周期的第一操作阶段期间，使用自动归零比较器将动态电流镜的输出电压充电到第二电容器（C2）中，并且检测 在DC-DC转换器的第一工作阶段结束时，通过将在第一操作期间存储在第二电容器中的电压与在第一操作期间的输出电压进行比较，电力开关的导通电压（VDS（t = TCLK）） 在第二阶段的动作电流镜（Φ2）对应于电源开关的非导通周期。